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Proposed Rule

Federal Motor Vehicle Safety Standards; Side Impact Protection; Fuel System Integrity

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Start Preamble

AGENCY:

National Highway Traffic Safety Administration (NHTSA), Department of Transportation.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

Pursuant to the agency's grant of a petition for rulemaking from Mr. James E. Stocke, NHTSA proposes to update the Federal motor vehicle safety standards on side impact protection and fuel system integrity by requiring that radial tires of certain specifications, rather than bias ply tires, be used on the moving barriers specified in these standards. In conjunction with that proposal, NHTSA also proposes to delete certain outdated or incorrect specifications for the moving barriers in those standards.

DATES:

You should submit your written comments so that they are received by December 10, 2001.

ADDRESSES:

You may submit your comments in writing to: Docket Management, Room PL-401, 400 Seventh Street, SW, Washington, DC, 20590. Alternatively, you may submit your comments electronically by logging onto the Docket Management System (DMS) website at http://dms.dot.gov. Click on “Help & Information” or “Help/Info” to view instructions for filing your comments electronically. Regardless of how you submit your comments, you should mention the docket number of this document.

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FOR FURTHER INFORMATION CONTACT:

For technical and policy issues: Dr. William Fan, Office of Crashworthiness Standards, NPS-11, National Highway Traffic Safety Administration, 400 Seventh Street, SW, Washington, DC 20590. Telephone: (202) 366-4922. Fax: (202) 366-4329.

For legal issues: Nancy Bell, Attorney Advisor, Office of the Chief Counsel, NCC-20, National Highway Traffic Safety Administration, 400 Seventh Street, SW, Washington, DC 20590. Telephone: (202) 366-2992. Fax: (202) 366-3820.

End Further Info End Preamble Start Supplemental Information

SUPPLEMENTARY INFORMATION:

I. Background

Federal Motor Vehicle Safety Standard (FMVSS) No. 214, Side impact protection (49 CFR 571.214), and FMVSS No. 301, Fuel system integrity (49 CFR 571.301), specify impact tests using moving barriers. Paragraph S6.10 of FMVSS No. 214 contains specifications for a moving deformable barrier. FMVSS No. 301 contains specifications for two 1,814 kilogram (4,000 pound) rigid moving barriers, a flat rigid moving barrier (Paragraphs S7.2 and S7.3) [1] and a contoured rigid Start Printed Page 51630moving barrier (Paragraph S7.5). Both FMVSS No. 301 barriers are used to assess vehicle fuel system integrity. The FMVSS No. 301 flat rigid moving barrier is used for testing passenger cars, multipurpose passenger vehicles, trucks and buses with a gross vehicle weight rating (GVWR) of 4,536 kilograms (10,000 pounds) or less, and the FMVSS No. 301 contoured rigid barrier is used for testing large school buses with a GVWR greater than 4,536 kilograms (10,000 pounds). The FMVSS No. 214 barrier is a 1,367 kilogram (3,000 pound) moving deformable barrier used for testing passenger cars, and multipurpose passenger vehicles, trucks and buses with a GVWR of 2,722 kilograms (6,000 pounds) or less in side impact crashes. G78-15 bias ply tires are currently specified for the FMVSS No. 301 barriers.[2]

The tire specifications for the FMVSS No. 214 moving barrier are not set out in FMVSS No. 214. Rather, S6.10 of FMVSS No. 214 refers to the moving barrier specified in 49 CFR Part 587, Side Impact Moving Deformable Barrier. The tire specifications for that barrier are contained in Drawing DSL-1278, Sheet 2 of 2, Item -11 and Note 8. Item -11 specifies “Bias belted tire (BF Goodrich—G78-15 CLM).” On October 1991, Note 8 was added to drawing DSL-1278 that states “Bias belted tire, size P215/75B15, may be substituted for that specified in -11. Inflate to recommended pressure.”

II. Petition for Rulemaking

On February 3, 2000, Mr. James E. Stocke, a retired automotive safety engineer, submitted a petition for rulemaking requesting that NHTSA amend FMVSS No. 301 to require that the moving barrier assembly be equipped with P205/75R15 radial tires inflated to 207 kPa (30 psi), replacing the currently required G78-15 bias ply tires inflated to 165 kPa (24 psi).

In his petition, Mr. Stocke stated that the bias tire size designation referenced in FMVSS No. 301 was outdated 15 years ago and that bias tires are no longer readily available because they have been replaced with radial tires. Mr. Stocke noted that the Society of Automotive Engineers, Inc. (SAE) J972 Recommended Practice “Moving Barrier Collision Tests” was revised (in August 1997) to specify both P205/75R15 radial tires and G78-15 bias ply tires for use on moving barriers.[3]

Additionally, Mr. Stocke stated that a P205/75R15 tire inflated to 207 kPa (30 psi) is equivalent to a G78-15 tire inflated to 165 kPa (24 psi). Also, he asserted that the tread width specification for the bias ply tire would not be necessary for a radial tire specification because the radial tire size designation (width to height ratio) is sufficient to define the tread width. Accordingly, Mr. Stocke suggested amending FMVSS No. 301 to read as follows: “The moving barrier assembly is equipped with P205/75R15 pneumatic tires inflated to 207 kPa.” In a letter dated August 16, 2000, NHTSA granted Mr. Stocke's petition for rulemaking.

III. NHTSA's Response to Petition

In reviewing Mr. Stocke's petition, we were guided by a number of considerations. First, with the increased use of the radial tire design over the past 30 years in the U.S., the bias ply tire design has become virtually obsolete.[4] The manufacture and use of bias ply tires has largely been replaced by the manufacture and use of radial tires. Consequently, bias tires are not readily available to testing laboratories at present and will become even more difficult for the laboratories to obtain in the future. Also, as the petitioner points out, the SAE Recommended Practice for “Moving Barrier Collision Tests” now includes specifications for radial tires as well as for bias ply tires. Both P205/75R15 and P215/75R15 radial tires are readily available at present and are widely recommended for use by vehicle manufacturers on passenger cars, small passenger vans, and small sport utility vehicles.

Another consideration for the agency is the possible effect on ride height (the height at the center of gravity) and vertical motion (bounce) of a moving barrier if tires different from those currently specified in FMVSS Nos. 214 and 301 are used on those barriers. Bias ply tires and radial tires are different in design and construction, and they exhibit different performance characteristics. For instance, bias ply tires have their inner carcass cords laid at an angle of about 50 degrees to the center line of the tread, and cords in successive plies (two or four) usually run in a criss-cross fashion—an arrangement which serves to equalize cord tensions. On the other hand, radial tires have cords which run at right angles to the center line of the tread and parallel to the radius of the tire. The radial construction creates a tread which is stiffer and a sidewall which is more flexible than that of a bias ply tire. These factors may affect the performance of moving barriers as discussed below.

The moving barrier tests in FMVSS Nos. 214 and 301 specify a static barrier ride height, an important impact parameter measurement. Further, the Laboratory Test Procedure in FMVSS No. 214 provides a guideline for barrier vertical displacement. Because a radial tire has a lower profile and a more flexible sidewall than a bias ply tire, the use of radial tires, rather than bias ply tires, on the moving barriers specified in FMVSS Nos. 214 and 301 could affect the barrier ride height (the center of gravity height and/or barrier contact height). Additionally, if an improper tire inflation pressure is used, it may affect the barrier's vertical motion as it is being towed during the test.

IV. Related Barrier Tire Research

P215/75R15 Radial Tires

Recently, Ford Motor Company (Ford) conducted a barrier tire study (Ford Study) to better understand the effect of tires on testing done pursuant to FMVSS No. 214 and 96/27/EC, the European Union side impact directive.[5] This study included investigating vertical and horizontal displacements of the barriers, quantifying cart/barrier behavior at impact, and evaluating factors that may contribute to noncompliance with the requirements of the regulations.

The Ford Study was based on data derived from 34 U.S. side impact tests and 16 European side impact tests conducted in 1997.[6] Three principal Start Printed Page 51631variables in the study were (1) release mechanisms (pins/chains), (2) tire types (bias/radial) and (3) tire pressures (103 kPa (15 psi)/221 kPa (32 psi)). The study indicated that all 34 U.S. side impact tests were within the horizontal displacement specification of +/−50 mm (2 inches) and approximately three-fourths of the tests were within the vertical displacement guideline of +/−20 mm (0.8 inch). More specifically, the test data indicated that the barriers with the P215/75R15 radial tires inflated to 221 kPa (32 psi) were able to meet the +/−20 mm (0.8 inch) guideline in almost 100% of the tests. After careful review of this extensive study, NHTSA has tentatively concluded that the P215/75R15 radial tire inflated to 221 kPa (32 psi) is an appropriate alternative to the G78-15 bias ply tire for use on the FMVSS No. 214 barrier.

P205/75R15 Radial Tires

As mentioned previously, SAE J972 was recently revised to specify that P205/75R15 radial tires inflated to 207 kPa (30 psi), as well as G78-15 bias ply tires inflated to 165 kPa (24 psi), may be used on all 1,814 kilogram (4,000 pound) moving barriers. Because SAE will not issue a Recommended Practice that has not been approved by its test engineers and auto industry representatives, NHTSA believes that vehicle manufacturers and their test laboratories have already tested and accepted the revised SAE J972 Recommended Practice. NHTSA, following the SAE Recommended Practice, tentatively concludes that the P205/75R15 tires inflated to 207 kPa (30 psi) are appropriate for use on both of the 1,814 kilogram (4,000 pound) moving barriers specified in FMVSS No. 301. Accordingly, NHTSA has tentatively concluded that the P205/75R15 radial tires inflated to 207 kPa (30 psi) is an appropriate alternative to the G78-15 bias ply tire for use on the FMVSS No. 301 barriers.

V. Agency Proposal

A. Radial Tire Size and Inflation Pressure

While NHTSA has tentatively made conclusions concerning the use of one tire (the P215/75R15 tire inflated to 221 kPa (32 psi)) for the FMVSS No. 214 moving barrier and another tire (the P205/75R15 tire inflated to 207 kPa (30 psi)) for the FMVSS No. 301 moving barriers, the agency recognizes that it would be easier for test laboratories to use only one size tires for FMVSS Nos. 214 and 301 moving barriers. The agency therefore proposes specifying either P215/75R15 tires inflated to 221 kPa (32 psi) for use on FMVSS Nos. 214 and 301 moving barriers or P205/75R15 tires inflated to 207 kPa (30 psi) for use on FMVSS Nos. 214 and 301 moving barriers. In other words, NHTSA plans to pick one of these tires and specify it in the final rule for both barriers.

As discussed above, the ride height and vertical motion of a moving barrier determine the impact location and the height of the moving barrier can have an effect on test results. Prior to making a final decision, the agency will assess the extent to which the substitution of a single tire may have unintended effects on either (1) the ride height, or (2) the impact performance of the FMVSS Nos. 214 and 301 moving barriers. For example, in attempting to find a set of appropriate radial tires (tire size and inflation pressure) for use on the FMVSS No. 214 barrier, NHTSA is concerned that a set of four incorrectly inflated tires could result in excessive barrier vertical motion during the towing process, which could make it difficult to stay within the +/−20 mm (0.8 inch) vertical displacement guideline.[7] NHTSA solicits comments and laboratory test data concerning these matters.

B. Other Issues

Tread Width

NHTSA concurs with petitioner's comments that the tread width specification for radial tires is not necessary since the radial tire size designation is sufficient to define tread width. For instance, the first three numbers in the P205/75R15 radial tire designation indicate that the tire width is 205 mm. The Tire and Rim Association, Inc. Yearbooks contain a chart to define the maximum dimensions of grown tires in service.[8] According to the chart, the maximum tire tread width of a 75 series aspect ratio tire is 80 percent of the overall width. Mr. Stocke is correct that the tread width of P205/75R15 tires (205 mm × 0.8 = 164 mm) is within the specification in FMVSS No. 301 for tire width of 152 mm +/−25 mm (6.0 in. +/−1.0 in.). Likewise, the P215/75R15 tires are within that specification (215 mm × 0.8 = 172 mm). In addition, FMVSS No. 214 does not specify any tire tread width. Therefore, NHTSA proposes that the tread width specification be deleted from the tire specifications in FMVSS No. 301.

Moments of Inertia

Data received from NHTSA's contractors and from the Vehicle Research and Test Center at East Liberty, Ohio (VTRC) indicate that it is extremely difficult, if not impossible, to construct the FMVSS No. 301 contoured moving barrier in accordance with both the center of gravity and the moments of inertia specified in FMVSS No. 301.[9]

The FMVSS No. 301 moving contoured barrier test was initially based on an old SAE Recommended Practice which included specifications for moments of inertia, as well as dimensional drawings and a specified center of gravity. In its rulemaking for the FMVSS No. 301 contoured moving barrier (40 FR 18469, April 28, 1975; 40 FR 47790, October 15, 1975), NHTSA retained the SAE Recommended Practice specifications of measurement, but made modifications to the original SAE design by lowering the front face of the barrier design by 178 mm (7 inches). With this modification, the moments of inertia derived from the SAE Recommended Practice are difficult to achieve. However, there has been no reason to believe that the actual barriers utilized by the agency and by manufacturers have yielded inappropriate results.

Based on the current measurements, excepting the moments of inertia, the FMVSS No. 301 contoured moving barrier can be constructed to the barrier specifications with the dimensional drawings and the specified center of gravity. There are no moments of inertia specified for the FMVSS No. 301 flat moving barrier. Therefore, NHTSA proposes that the moment of inertia specifications for the contoured moving barrier be removed from FMVSS No. 301.

VI. Rulemaking Analyses and Notices

Executive Order 12866 (Federal Regulation) and DOT Regulatory Policies and Procedures

This notice has not been reviewed under E.O. 12866. After considering the Start Printed Page 51632impacts of this rulemaking action, we have determined that the action is not significant within the meaning of the Department of Transportation regulatory policies and procedures. The intent of the rulemaking action is to update regulatory procedures that have been in effect for over 25 years. In most cases, the effect of the proposed amendments would be to relax or eliminate burdens on regulated entities. This action does not involve a substantial public interest or controversy. The rulemaking action would not have a substantial impact on any transportation safety program or on state and local governments. The impacts are so minimal as not to warrant the preparation of a full regulatory evaluation. The tires specified in the proposed rule are more readily available than those currently specified, and they are already widely recommended by voluntary standards organizations for use by vehicle manufacturers for testing. Accordingly, there will be no increase in the cost of tires used for testing, and we do not anticipate any impact on the ability to conduct valid tests or any other impact on the cost or ease of testing.

Regulatory Flexibility Act

In compliance with the Regulatory Flexibility Act (5 U.S.C. 601-612), we have evaluated the effects of this rule on small entities. NHTSA certifies that this action would not have a significant economic impact on a substantial number of small entities. This action merely replaces an outdated tire specification for testing devices with an equivalent current tire specification.

Paperwork Reduction Act

Under the Paperwork Reduction Act of 1995 (PRA) (44 U.S.C. 3501, et. seq.), Federal agencies must obtain approval from the Office of Management and Budget (OMB) for each collection of information they conduct, sponsor, or require through regulations. NHTSA has reviewed this proposal and determined that it does not contain collection of information requirements.

Unfunded Mandates Reform Act of 1995

This rule would not impose a Federal mandate resulting in the expenditure by State, local, and tribal governments, in the aggregate, or by the private sector, of $ 100 million or more in any one year. (2 U.S.C. 1531 et seq.).

Executive Order 12778 (Civil Justice Reform)

This proposed rule would not have any retroactive effect. Under section 49 U.S.C. 30103, whenever a Federal motor vehicle safety standard is in effect, a state may not adopt or maintain a safety standard applicable to the same aspect of performance which is not identical to the Federal standard, except to the extent that the state requirement imposes a higher level of performance and applies only to vehicles procured for the State's use. 49 U.S.C. 30161 sets forth a procedure for judicial review of final rules establishing, amending or revoking Federal motor vehicle safety standards. That section does not require submission of a petition for reconsideration or other administrative proceedings before parties may file suit in court.

Executive Order 13045 (Protection of Children)

We have analyzed this action under Executive Order 13045, Protection of Children from Environmental Health Risks and Safety Risks. This rule is not an economically significant rule and does not concern an environmental risk to health or safety that may disproportionately affect children.

Executive Order 12630 (Taking of Private Property)

This rule will not effect a taking of private property or otherwise have taking implications under Executive Order 12630, Governmental Actions and Interference with Constitutionally Protected Property Rights.

National Environmental Policy Act

The agency has analyzed this action for the purposes of the National Environmental Policy Act of 1969, as amended (42 U.S.C. 4321 et seq.) and has determined that this action would not have any effect on the quality of the environment.

Executive Order 13132 (Federalism)

E.O. 13132 (64 FR 43255, August 10, 1999), revokes and replaces E.O.'s 12612 “Federalism” and 12875 “Enhancing the Intergovernmental Partnership.” E.O. 13132 requires NHTSA to develop an accountable process to ensure “meaningful and timely input by State and local officials in the development of regulatory policies that have federalism implications.” E.O. 13132 defines the term “Policies that have federalism implications” to include regulations that have “substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.” Under E.O. 13132, NHTSA may not issue a regulation that has federalism implication, that imposes substantial direct compliance costs, and that is not required by statute, unless the Federal government provides the funds necessary to pay the direct compliance costs incurred by State and local governments, or NHTSA consults with State and local officials early in the process of developing the proposed regulation.

The proposed rule would not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government as specified in E.O. 13132. Thus, the requirements of section 6 of the Executive Order do not apply to this rule.

Plain Language

E.O. 12866 requires each agency to write all rules in plain language. Application of the principles of plain language include consideration of the following questions:

—Have we organized the material to suit the public's needs?

—Are the requirements in the proposed rule clearly stated?

—Does the proposed rule contain technical language or jargon that is unclear?

—Would a different format (grouping and order of sections, use of heading, paragraphing) make the rule easier to understand?

—Would more (but shorter) sections be better?

—Could we improve clarity by adding tables, lists, or diagrams?

—What else could we do to make the rule easier to understand?

If you have any responses to these questions, please include them in your comments on this document.

VII. Comments

How Do I Prepare and Submit Comments?

Your comments must be written and in English. To ensure that your comments are correctly filed in the Docket, please include the docket number of this document in your comments.

Your comments must not be more than 15 pages long. (49 CFR 553.21). We established this limit to encourage you to write your primary comments in a concise fashion. However, you may attach necessary additional documents to your comments. There is no limit on the length of the attachments.

Please submit two copies of your comments, including the attachments, to Docket Management at the address given above under ADDRESSES. Start Printed Page 51633

How Can I Be Sure That My Comments Were Received?

If you wish Docket Management to notify you upon its receipt of your comments, enclose a self-addressed, stamped postcard in the envelope containing your comments. Upon receiving your comments, Docket Management will return the postcard by mail.

How Do I Submit Confidential Business Information?

If you wish to submit any information under a claim of confidentiality, you should submit three copies of your complete submission, including the information you claim to be confidential business information, to the Chief Counsel, NHTSA, at the address given above under FOR FURTHER INFORMATION CONTACT. In addition, you should submit two copies, from which you have deleted the claimed confidential business information, to Docket Management at the address given above under ADDRESSES. When you send a comment containing information claimed to be confidential business information, you should include a cover letter setting forth the information specified in our confidential business information regulation. (49 CFR Part 512.)

Will the Agency Consider Late Comments?

We will consider all comments that Docket Management receives before the close of business on the comment closing date indicated above under DATES. To the extent possible, we will also consider comments that Docket Management receives after that date.

How Can I Read the Comments Submitted by Other People?

You may read the comments received by Docket Management at the address given above under ADDRESSES. The hours of the Docket are indicated above in the same location.

You may also see the comments on the Internet. To read the comments on the Internet, take the following steps:

(1) Go to the Docket Management System (DMS) Web page of the Department of Transportation (http://dms.dot.gov/​).

(2) On that page, click on “search.”

(3) On the next page (http://dms.dot.gov/​search/​), type in the four-digit docket number shown at the beginning of this document. Example: If the docket number were “NHTSA-1999-1234,” you would type “1234.” After typing the docket number, click on “search.”

(4) On the next page, which contains docket summary information for the docket you selected, click on the desired comments.

You may download the comments. However, since the comments are imaged documents, instead of word processing documents, the downloaded comments are not word searchable.

Please note that even after the comment closing date, we will continue to file relevant information in the Docket as it becomes available. Further, some people may submit late comments. Accordingly, we recommend that you periodically check the Docket for new material.

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List of Subjects

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In consideration of the foregoing, we propose to amend 49 CFR parts 571 and 587 as follows:

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PART 571—FEDERAL MOTOR VEHICLE SAFETY STANDARDS

1. The authority citation for part 571 would continue to read as follows:

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Authority: 49 U.S.C. 322, 30111, 30115, 30166 and 30177; delegation of authority at 49 CFR 1.50.

End Authority

2. Section 571.301 would be amended by revising S7.5.2, S7.5.4 and S7.5.5; by removing S7.5.6; and by adding S7.6 to read as follows:

Standard No. 301; Fuel system integrity.
* * * * *

S7.5.2 The moving contoured barrier, including the impact surface, supporting structure, and carriage, has a mass of 1,814 kg ± 23 kg with the mass distributed so that 408 kg ± 11 kg is at each rear wheel and 499 kg ± 11 kg is at each front wheel. The center of gravity is located 1,372 mm ± 38 mm rearward of the front wheel axis, in the vertical longitudinal plane of symmetry, 401 mm above the ground.

* * * * *

S7.5.4 The concrete surface upon which the vehicle is tested is level, rigid, and of uniform construction, with a skid number of 75 when measured in accordance with American Society of Testing and Materials Method E; 274-65T at 64 km/h, omitting water delivery as specified in paragraph 7.1 of that method.

S7.5.5 The barrier assembly is released from the guidance mechanism immediately prior to impact with the vehicle.

S7.6

[Alternative 1]

The moving barrier assemblies specified in S7.2, S7.3 and S7.5 are equipped with P215/75R15 pneumatic tires inflated to 221 kPa.

[Alternative 2]

The moving barrier assemblies specified in S7.2, S7.3 and S7.5 are equipped with P205/75R15 pneumatic tires inflated to 207 kPa.

* * * * *

3. Figure 2 at the end of section 571.301 would be revised to read as follows: [blank page for figure 2]

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End Part Start Part Start Printed Page 51635

PART 587—DEFORMABLE BARRIERS

4. The authority citation for part 587 would continue to read as follows:

Start Authority

Authority: 49 U.S.C. 322, 30111, 30115, 30117, 30166 and 30177; delegation of authority at 49 CFR 1.50.

End Authority

5. Section 587.6 would be amended by revising paragraph (b)(1) to read as follows:

General description.
* * * * *

(b)(1) The specifications for the final assembly of the moving deformable barrier are provided in the drawings shown in DSL-1278, dated [date of the final drawing change].

* * * * *
Start Signature

Issued on: October 4, 2001.

Stephen R. Kratzke,

Associate Administrator for Safety Performance Standards.

End Signature End Part End Supplemental Information

Footnotes

1.  The FMVSS No. 301 flat rigid moving barrier is identical to the moving barrier specified for the lateral moving barrier test in paragraph S8.2 of FMVSS No. 208, Occupant crash protection (49 CFR 571.208). At this time, the tire specifications in S8.2 of FMVSS No. 208 will not be amended. FMVSS No. 208's lateral moving barrier crash test was part of an optional requirement for automatic restraint systems which can no longer be utilized by manufacturers to certify their vehicles. Vehicle manufacturers are currently required to fulfill a more stringent requirement by installing air bags and Type 2 seat belts in both front outboard designated seating positions.

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2.  Paragraph S7.5.4 of FMVSS No. 301 specifies G78-15 bias ply tires for use on the contoured rigid moving barrier. The requirements for the FMVSS No. 301 flat rigid moving barrier do not specify bias ply tires, but, in practice, the flat rigid moving barrier utilizes the identical under-structure and G78-15 bias ply tires as the contoured rigid moving barrier.

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3.  SAE is an organization which develops voluntary standards for aerospace, automotive and other industries. Many of SAE's recommended practices are developed using technical information supplied by vehicle manufacturers and automotive test laboratories.

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4.  According to the Rubber Manufacturers Association's “Factbook 2000,” original equipment radial tires shipment sales surpassed those of bias ply tires by a wide margin in the early 1970s. In 1999, radial tires shipments comprised 99.8% of the replacement market.

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5.  Ford engineers have provided a copy of their summary report to NHTSA. Test details are not currently available. A copy of the summary report is available in the docket for this Notice.

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6.  The Ford Study recommended conducting eight additional tests to measure the barrier motion. Ford did not conduct the additional tests because it concluded that no new information would be derived from resulting data. NHTSA concurs with Ford's decision that the 34 Ford side impact tests and the 16 European tests provide a sufficient data basis for analysis.

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7.  To control the impact height in the impact test in FMVSS No. 214, NHTSA's Office of Vehicle Safety Compliance specifies a vertical displacement guideline of +/−20 mm (0.8 inch) in its Laboratory Test Procedure. (This guideline only applies to NHTSA contractors conducting FMVSS No. 214 side impact compliance tests.)

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8.  A “grown” tire means that a tire has experienced a growth or a stretch of its fabric during service. Some tire tables show an allowance on the maximum tire dimensions to compensate for this “growth.” To prevent the tire from rubbing the vehicle, vehicle manufacturers use this maximum number in their vehicle designs.

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9.  The moment of inertia is the quantitative measure of the rotational inertia of a body, i.e., the opposition that the body exhibits to having its speed of rotation about an axis altered by the application of a torque (turning force).

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BILLING CODE 4910-59-P

BILLING CODE 4910-59-C

[FR Doc. 01-25428 Filed 10-9-01; 8:45 am]

BILLING CODE 4910-59-P